Dr. Takemoto earned his medical degree at the University of California, Irvine School of Medicine. He completed a pediatrics residency at Children's Hospital Los Angeles, an oncology fellowship at Tokyo’s National Children's Medical Research Center and a pediatric hematology/oncology fellowship at the Dana-Farber Cancer Institute.

Prior to joining the Johns Hopkins faculty in 1999, he was an instructor in pediatric hematology/oncology at Harvard Medical School. In addition to his duties at Johns Hopkins, Dr. Takemoto also serves as an adjunct investigator in pediatric oncology at the National Cancer Institute.

Dr. Takemoto is a member of the American Association of Immunologists, the American Society of Hematology, and the American Society of Pediatric Hematology/Oncology.